Sports-related measurement systems have grown dramatically in sophistication, over the years. With respect to bicycling, such systems have evolved from older, heavy speedometers, and the like, to modern electronic units capable of monitoring and displaying a number of performance characteristics.
So-called bicycle computers, which for example, track and electronically display speed, distance, and so forth, are now common in the art. The following examples are illustrative of known systems of this type. In U.S. Pat. No. 4,642,606, entitled "DATA DISPLAY UNIT FOR A BICYCLE" to Tsuyama, there is disclosed a handlebar-mounted display unit to which a wheel and crank sensor are communicatively interfaced, affording the calculation of running data such as speed, distance, average speed, maximum speed and so forth, based upon electrical pulses received from the wheel and crank sensors. U.S. Pat. No. 4,862,395 entitled "DATA DISPLAY INSTRUMENT FOR A BICYCLE" to Fey et al. includes most of the same features of the device of Tsuyama, but claims to improve upon the display by providing an analog scale field to display traveling speed and pedaling speed on a momentary, more readable basis. The '395 patent also includes a sensor associated with wheel rotation, and an additional sensor associated with pedal speed to determine cadence. In addition to the devices just described, others exist, both in patent literature and as commercially available products.
Bicycle computers also exist which have output ports enabling the device to be interfaced to a commercially available personal computer. The invention, "BICYCLE COMPUTER WITH MEMORY AND MEANS FOR COMPARING PRESENT AND PAST PERFORMANCE IN REAL TIME," disclosed in U.S. Pat. No. 5,335,188 to Brisson, for example, discloses a device for monitoring and comparing present, past and ideal performance on an exercise machine such as a bicycle. The system operates under a predetermined set of user-controlled instructions, to store a set of performance data in memory, which can then be compared against a stored, user selected performance data. Comparisons among these various data sets may then be displayed.
The exercise computer of Brisson includes a connector (65) for linking to an external computer, but the capabilities involved are extremely limited. In one example given, data in the memory of the computer itself may be transmitted to the external computer for "safekeeping," then transferred back to the cycle computer at a later time. The specified purpose is to ensure that the data are not lost should the memory suffer from a power failure, should the cycle computer be stolen. Alternatively, if the user rides on many different routes, the cycle computer may not have enough memory to save all ride data, in which case the connector (65) may be used to transfer a larger number of pace files to an external computer such as a PC. Thus, according to the '188 patent, although a computer interface is provided, it is essentially limited in function to that of a memory expansion port.
Despite the various speed, distance and cadence functions available through existing cycle-mounted computers, none receive geographical coordinates through, for example, a global positioning satellite (GPS) receiver. Although a variety of vehicle-oriented tracking and mapping systems do exist which include GPS capabilities, none exist for bicycles. However, the inclusion of such a capability within a bicycle computer provides a number of unique advantages, as will be explained in the sections herein detailing the instant invention. As one such advantage, by utilizing an additional satellite to obtain altitude as well as longitude/latitude coordinates, the cyclist may be provided with elevation as well as geographic location information, which may be particularly useful in determining performance, endurance, and other characteristics. Moreover, by obtaining and storing position and/or altitude information, these characteristics may be tracked in terms of location and/or altitude, enabling the cyclist to visualize speed, cadence and other external and/or physiological characteristics as a function of geographical position, further allowing performance attributes to be tracked and plotted, for example, on an external personal computer. By combining GPS capabilities with the various functional and performance monitoring and tracking capabilities disclosed herein, the rider may not only visualize performance as a function of geometry, including incline, but will also be more equipped to optimize performance, by determining when cadence, gearshifting, and other riding changes were, or should have been, executed.